Thomas of Lancaster, 1st Duke of Clarence

Thomas of Lancaster, 1st Duke of Clarence (29 September 1388-22 March 1421) was the second son of King Henry IV of England and Mary of Bohun. He took part in the military campaigns of his brother, Henry V, and he was killed at the Battle of Bauge in 1421.

Biography
Thomas of Lancaster was born in Kenilworth Castle, Warwickshire, England on 29 September 1388, the son of Henry Bolingbroke and Mary of Bohun. In 1411, he married the widow of John Beaufort, 1st Earl of Somerset, and he was ennobled as "Duke of Clarence" a year later. During the wars of his elder brother Henry V of England in France, Clarence commanded the besieging force at Rouen, and he launched a chevauchee through Anjou and the County of Maine with 4,000 men in 1421. On 22 March 1421, he underestimated the size of a Franco-Scottish army at Bauge and decided to launch a surprise cavalry attack against it, and he was unhorsed in the battle and finished off with a Scottish knight's mace.